“Children love to blow out their candles while their friends are singing ‘Happy birthday,’” the document states. “To prevent the spread of germs when the child blows out the candles, parents should either provide a separate cupcake, with a candle if they wish, for the birthday child and enough cupcakes for all the other children.”

Daycare staff should also be required to clean toys, doorknobs, floors and cushion covers with germ-killing disinfectant on a daily basis, while youngsters must wash their hands with alcohol-based sanitizer before and after playing in sandpits, says the NHMRC.

But Australian doctors say the guidelines go too far, noting how exposure to bacteria is essential for the development of a healthy immune system.

“If somebody sneezes on a cake, I probably don’t want to eat it either — but if you’re blowing out candles, how many organisms are transferred to a communal cake, for goodness’ sake?” AMA president Steve Hambleton told News Ltd.

“It’s normal and healthy to be exposed to a certain amount of environmental antigens that build up our immune systems. If you live in a plastic bubble you’re going to get infections [later on] that you can’t handle.”

The NHMRC also urged parents to allow their children to stay at home if feeling unwell in order to avoid unnecessarily spreading infections to their school classmates. Schools should ignore doctors’ letters that state a pupil is healthy if teachers suspect otherwise, said the council.